Process for making a fluorescent product



I Patented Apr. 9, 1929.

UNITED STATES PATENT OFFICE.

JOHN 0. BLACK, LOS AN GELES, WIRT D.

RIAL, 0]! L08 AN GELES COUNTY, AND JOHN R. HCCONNELL, OI WHITTEB, CALIFORNIA, ASSIGNOBS TO PAN AMERICAN PETROLEUM COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALI- romna v 4 R0 Drawing. Application filed Kay 9,

This invention relates to a fluorescent product andprocess of making same for use in imparting a desired green fluorescence to and improving the quality of lubricating 011 5 stock, and is a continuation in part of the pending application of John C. Black, Wirt D. Rial and John R. McConnell, Process of imparting fluorescence to oil, Serial Number 141,424, filed October 13, 1926. As stated in this pending application, the trade associates a green fluorescent lubricating oil stock with quality, therefore, it is desirable for commercial reasons as well as from a quality standpoint to impart a green fluorescence to '15 certain grades of lubricating oil stock.

It is generally known to those familiar with the art that certain lubricating 011 stocks without this green fluorescence may acquire a blue fluorescence, and that this p blue fluorescent lubricating oil stock is usually an oil which has been derived from a crude petroleum oil by distillation termed overhead stock.

In the manufacture of lubricating oil from a crude oil free from asphalt, or substantially free from asphalt, a green fluorescence will result in the residuum remaining after the removal of the lower boiling oils, even though the residuum has been subjected to a light cracking to crystallize the amorphous wax contained therein, and a lubricating oil stock can be produced from the samewith a desired green fluorescence. Also a commercial production of a lubricating oil with a green fluorescence has been produced by cracking lightly a lubricating oil distillate derived from a California asphalt mixed base petroleum oil which contained approximatcly 4% of parafline wax.

It is an object of this invention to produce a concentrated extract of green fluorescent bodies, which when added to and commingled with a lubricating oil stock which may or may not be generally characterized by a bluish color when viewed by reflected li ht will then acquire a green fluorescence t at will be generally characterized by a green color when viewed by reflected light, and will be further characterized by a red, reddish brown, yellow or. shades of yellow when viewed by transmitted light.

We have found that certain bodies exrnocnss r03 name A rnuonnscnn'r rnonvcr.

1927. Serial No. 189,449."

tracted from coal tar, coal tar pitch, water gas tar, water gas tar pitch, and high boilmg distillates of the same, will impart to a lubricating oil stock a green fluorescence, and will produce thereby a lubricating oil stock improved in quality and color.

The process of this application consists in concentrating these bodies in a solvent or medium, and then adding the solvent or medium containing the fluorescent bodies, to a lubricating oil stock, in quantities sufficient to produce a desired green fluorescence to said lubricating oil stock. It is an important advantage of this process that by employing a concentrated fluorescent extract substantially no impurities associated with the fluorescent material are introduced into the oil.

As a specific example of a material suit able for making the extract or medium containing these dissolved or suspended greenfluorescent bodies, not contain hydrocarbons boiling at lower temperatures than the lubricating oil stock is preferred, although coal tar and water gas tars may be employed, and the low boiling hydrocarbons eliminated after the extract or medium containing the green fluorescent bodies has been admixed with the lubricating oil stock.

The solvent or medium to be employed for extracting the green fluorescent bodies may be any pure hydrocarbon, such for example as gasoline, benzol and the, like, or preferably a higher boiling petroleum oil such as a lubricating oil stock. lVhen employing volatile solvents, the extract is made by commingling comminuted coal tar pitch with the solvent, preferably near the boiling point of the solvent. The extract in the required proportion is added to the lubricating oil stock and the solvent removed by volatilization.

We have found it more desirable, however, to employ higher boiling hydrocarbon oils, such for example as a lubricating oil having a flash oint the same or higher than the lubricatlng oil stock to which the fluorescent extract is to be added. As a specific example for making the fluorescent extract, the solvent or medium, preferably lubricating oil stock, is commingled with approximately one of the extract it may to twentyrtive percent by weight ofcomminuted coal tar pitcher high flash coal tar distillate at a tem erature of approximately 300 F., and pre erably in the presence of a decolorizing clay which will adsorb all-the undesired constituents of the coal tar pitch, or high flash coal tar distillate and also acts as a filter medium to prevent any finely comminuted particles from passing through with the solvent or medium. In case a decolorizing clay is not emplo ed in the manufacture be added-directly to the lubricating oil stock to which the fluorescent bodies are to be added, and thereafter clarified and decolorized to the desired degree by methods well known in the art.

In case a volatile solvent or medium is employed approximately the same amount of comminuted coal tar pitch, water gas pitch, or high flash distillates of the same, that is from one to as high as twenty-five percent by weight, or higher, is employed at a temperature preferably near the boiling point of the solvent or medium, although normal temperatures may be employed with such solvents as benzol or gasoline. After the pitch or distillate has been commingled at the required temperature with the solvent or medium it may or may not be filtered in the presence of a decolorizing clay. This concentrated extract is then added in the required amounts to lubricating oil stock and the volatile solvent separated by a distillation operation, or the lubricating oil stock commingled with the concentrated fluorescent cxtract may be first clarified and decolorized by means of a decolorizing clay and the volatile solvent thereafter separated by distillation.

In the preferred method of operating this invention the lubricating oil stock is acid treated before the addition of the concentrated green fluorescent extract, after which the sludge is removed, and the acid treated oil is then commingled with the required amount of concentrated green fluorescent extract, which is also preferably an acid treated lubricating oil stock containing a high percentage of green fluorescent bodies made in the manner heretofore described. The commingled lubricating oil stock containing the green fluorescent extract is then clarified and decolorized by methods well known in the art.

By the term solventor medium" we mean an oil which will dissolve or retain in a colloidal suspension the green fluorescent 'jbodies from coal tar pitch, coal tar, or distillates of the same While the process herein described is well adapted for carrying out the object of the present invention it is to be understood that various modifications and changes may be made without de arting from the spirit of the invention and the invention includes all such changes and modifications as appear in the scope of the appended claims.

We claim:

1. A process for the manufacture of a concentrated extract of green fluorescent bodies, which comprises commingling a mineral lubricating oil with a. coal tar product containing green fluorescent bodies, and then separating the lubricating oil containing the green fluorescent bodies from the insoluble coal tar residue.

1 2. A recess for the manufacture of an extract 0 gree fluorescent bodies, which comprises commingling a mineral lubricating oil with comminuted coal tar pitch at temperatures sufiicient to extract from the comminuted coal tar pitch green fluorescent bodies, and then separating the mineral lubricating oil containing the green fluorescent bodies from the residual coal tar pitch.

3. A process for the manufacture of an extract of green fluorescent bodies, which comprises commingling a hydrocarbon oil with a comminuted coal tar pitch and a decolorizing clay at temperatures substantially not less than 230 F., to extract from the coal tar pitch green fluorescent bodies, and then separating the hydrocarbon oil containing the green fluorescent bodies from the residual coal tar pitch and decolorizing clay.

4. A process for the manufacture of an extract of green fluorescent bodies, which comprises commingling a hydrocarbon oil with a comminuted coal tar pitch and a decolorizing clay at temperatures substantially not less than 230 F., to extract from the coal tar pitch green fluorescent bodies, and then separating the hydrocarbon oil containing the green fluorescent bodies from the residual coal tar pitch and decolorizing clay by filtration.

In testimony whereof we afiix our signatures.

JOHN G. BLACK. \VlRl l). RIAL. JOHN R. MCCON N ELL. 

